arch/x86/kvm/pmu_intel.c

   1 /*
   2  * KVM PMU support for Intel CPUs
   3  *
   4  * Copyright 2011 Red Hat, Inc. and/or its affiliates.
   5  *
   6  * Authors:
   7  *   Avi Kivity   <avi@redhat.com>
   8  *   Gleb Natapov <gleb@redhat.com>
   9  *
  10  * This work is licensed under the terms of the GNU GPL, version 2.  See
  11  * the COPYING file in the top-level directory.
  12  *
  13  */
  14 #include <linux/types.h>
  15 #include <linux/kvm_host.h>
  16 #include <linux/perf_event.h>
  17 #include <asm/perf_event.h>
  18 #include "x86.h"
  19 #include "cpuid.h"
  20 #include "lapic.h"
  21 #include "pmu.h"
  22
  23 static struct kvm_event_hw_type_mapping intel_arch_events[] = {
  24         /* Index must match CPUID 0x0A.EBX bit vector */
  25         [0] = { 0x3c, 0x00, PERF_COUNT_HW_CPU_CYCLES },
  26         [1] = { 0xc0, 0x00, PERF_COUNT_HW_INSTRUCTIONS },
  27         [2] = { 0x3c, 0x01, PERF_COUNT_HW_BUS_CYCLES  },
  28         [3] = { 0x2e, 0x4f, PERF_COUNT_HW_CACHE_REFERENCES },
  29         [4] = { 0x2e, 0x41, PERF_COUNT_HW_CACHE_MISSES },
  30         [5] = { 0xc4, 0x00, PERF_COUNT_HW_BRANCH_INSTRUCTIONS },
  31         [6] = { 0xc5, 0x00, PERF_COUNT_HW_BRANCH_MISSES },
  32         [7] = { 0x00, 0x30, PERF_COUNT_HW_REF_CPU_CYCLES },
  33 };
  34
  35 /* mapping between fixed pmc index and intel_arch_events array */
  36 static int fixed_pmc_events[] = {1, 0, 7};
  37
  38 static void reprogram_fixed_counters(struct kvm_pmu *pmu, u64 data)
  39 {
  40         int i;
  41
  42         for (i = 0; i < pmu->nr_arch_fixed_counters; i++) {
  43                 u8 new_ctrl = fixed_ctrl_field(data, i);
  44                 u8 old_ctrl = fixed_ctrl_field(pmu->fixed_ctr_ctrl, i);
  45                 struct kvm_pmc *pmc;
  46
  47                 pmc = get_fixed_pmc(pmu, MSR_CORE_PERF_FIXED_CTR0 + i);
  48
  49                 if (old_ctrl == new_ctrl)
  50                         continue;
  51
  52                 reprogram_fixed_counter(pmc, new_ctrl, i);
  53         }
  54
  55         pmu->fixed_ctr_ctrl = data;
  56 }
  57
  58 /* function is called when global control register has been updated. */
  59 static void global_ctrl_changed(struct kvm_pmu *pmu, u64 data)
  60 {
  61         int bit;
  62         u64 diff = pmu->global_ctrl ^ data;
  63
  64         pmu->global_ctrl = data;
  65
  66         for_each_set_bit(bit, (unsigned long *)&diff, X86_PMC_IDX_MAX)
  67                 reprogram_counter(pmu, bit);
  68 }
  69
  70 static unsigned intel_find_arch_event(struct kvm_pmu *pmu,
  71                                       u8 event_select,
  72                                       u8 unit_mask)
  73 {
  74         int i;
  75
  76         for (i = 0; i < ARRAY_SIZE(intel_arch_events); i++)
  77                 if (intel_arch_events[i].eventsel == event_select
  78                     && intel_arch_events[i].unit_mask == unit_mask
  79                     && (pmu->available_event_types & (1 << i)))
  80                         break;
  81
  82         if (i == ARRAY_SIZE(intel_arch_events))
  83                 return PERF_COUNT_HW_MAX;
  84
  85         return intel_arch_events[i].event_type;
  86 }
  87
  88 static unsigned intel_find_fixed_event(int idx)
  89 {
  90         if (idx >= ARRAY_SIZE(fixed_pmc_events))
  91                 return PERF_COUNT_HW_MAX;
  92
  93         return intel_arch_events[fixed_pmc_events[idx]].event_type;
  94 }
  95
  96 /* check if a PMC is enabled by comparing it with globl_ctrl bits. */
  97 static bool intel_pmc_is_enabled(struct kvm_pmc *pmc)
  98 {
  99         struct kvm_pmu *pmu = pmc_to_pmu(pmc);
 100
 101         return test_bit(pmc->idx, (unsigned long *)&pmu->global_ctrl);
 102 }
 103
 104 static struct kvm_pmc *intel_pmc_idx_to_pmc(struct kvm_pmu *pmu, int pmc_idx)
 105 {
 106         if (pmc_idx < INTEL_PMC_IDX_FIXED)
 107                 return get_gp_pmc(pmu, MSR_P6_EVNTSEL0 + pmc_idx,
 108                                   MSR_P6_EVNTSEL0);
 109         else {
 110                 u32 idx = pmc_idx - INTEL_PMC_IDX_FIXED;
 111
 112                 return get_fixed_pmc(pmu, idx + MSR_CORE_PERF_FIXED_CTR0);
 113         }
 114 }
 115
 116 /* returns 0 if idx's corresponding MSR exists; otherwise returns 1. */
 117 static int intel_is_valid_msr_idx(struct kvm_vcpu *vcpu, unsigned idx)
 118 {
 119         struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
 120         bool fixed = idx & (1u << 30);
 121
 122         idx &= ~(3u << 30);
 123
 124         return (!fixed && idx >= pmu->nr_arch_gp_counters) ||
 125                 (fixed && idx >= pmu->nr_arch_fixed_counters);
 126 }
 127
 128 static struct kvm_pmc *intel_msr_idx_to_pmc(struct kvm_vcpu *vcpu,
 129                                             unsigned idx)
 130 {
 131         struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
 132         bool fixed = idx & (1u << 30);
 133         struct kvm_pmc *counters;
 134
 135         idx &= ~(3u << 30);
 136         if (!fixed && idx >= pmu->nr_arch_gp_counters)
 137                 return NULL;
 138         if (fixed && idx >= pmu->nr_arch_fixed_counters)
 139                 return NULL;
 140         counters = fixed ? pmu->fixed_counters : pmu->gp_counters;
 141
 142         return &counters[idx];
 143 }
 144
 145 static bool intel_is_valid_msr(struct kvm_vcpu *vcpu, u32 msr)
 146 {
 147         struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
 148         int ret;
 149
 150         switch (msr) {
 151         case MSR_CORE_PERF_FIXED_CTR_CTRL:
 152         case MSR_CORE_PERF_GLOBAL_STATUS:
 153         case MSR_CORE_PERF_GLOBAL_CTRL:
 154         case MSR_CORE_PERF_GLOBAL_OVF_CTRL:
 155                 ret = pmu->version > 1;
 156                 break;
 157         default:
 158                 ret = get_gp_pmc(pmu, msr, MSR_IA32_PERFCTR0) ||
 159                         get_gp_pmc(pmu, msr, MSR_P6_EVNTSEL0) ||
 160                         get_fixed_pmc(pmu, msr);
 161                 break;
 162         }
 163
 164         return ret;
 165 }
 166
 167 static int intel_pmu_get_msr(struct kvm_vcpu *vcpu, u32 msr, u64 *data)
 168 {
 169         struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
 170         struct kvm_pmc *pmc;
 171
 172         switch (msr) {
 173         case MSR_CORE_PERF_FIXED_CTR_CTRL:
 174                 *data = pmu->fixed_ctr_ctrl;
 175                 return 0;
 176         case MSR_CORE_PERF_GLOBAL_STATUS:
 177                 *data = pmu->global_status;
 178                 return 0;
 179         case MSR_CORE_PERF_GLOBAL_CTRL:
 180                 *data = pmu->global_ctrl;
 181                 return 0;
 182         case MSR_CORE_PERF_GLOBAL_OVF_CTRL:
 183                 *data = pmu->global_ovf_ctrl;
 184                 return 0;
 185         default:
 186                 if ((pmc = get_gp_pmc(pmu, msr, MSR_IA32_PERFCTR0)) ||
 187                     (pmc = get_fixed_pmc(pmu, msr))) {
 188                         *data = pmc_read_counter(pmc);
 189                         return 0;
 190                 } else if ((pmc = get_gp_pmc(pmu, msr, MSR_P6_EVNTSEL0))) {
 191                         *data = pmc->eventsel;
 192                         return 0;
 193                 }
 194         }
 195
 196         return 1;
 197 }
 198
 199 static int intel_pmu_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 200 {
 201         struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
 202         struct kvm_pmc *pmc;
 203         u32 msr = msr_info->index;
 204         u64 data = msr_info->data;
 205
 206         switch (msr) {
 207         case MSR_CORE_PERF_FIXED_CTR_CTRL:
 208                 if (pmu->fixed_ctr_ctrl == data)
 209                         return 0;
 210                 if (!(data & 0xfffffffffffff444ull)) {
 211                         reprogram_fixed_counters(pmu, data);
 212                         return 0;
 213                 }
 214                 break;
 215         case MSR_CORE_PERF_GLOBAL_STATUS:
 216                 if (msr_info->host_initiated) {
 217                         pmu->global_status = data;
 218                         return 0;
 219                 }
 220                 break; /* RO MSR */
 221         case MSR_CORE_PERF_GLOBAL_CTRL:
 222                 if (pmu->global_ctrl == data)
 223                         return 0;
 224                 if (!(data & pmu->global_ctrl_mask)) {
 225                         global_ctrl_changed(pmu, data);
 226                         return 0;
 227                 }
 228                 break;
 229         case MSR_CORE_PERF_GLOBAL_OVF_CTRL:
 230                 if (!(data & (pmu->global_ctrl_mask & ~(3ull<<62)))) {
 231                         if (!msr_info->host_initiated)
 232                                 pmu->global_status &= ~data;
 233                         pmu->global_ovf_ctrl = data;
 234                         return 0;
 235                 }
 236                 break;
 237         default:
 238                 if ((pmc = get_gp_pmc(pmu, msr, MSR_IA32_PERFCTR0)) ||
 239                     (pmc = get_fixed_pmc(pmu, msr))) {
 240                         if (!msr_info->host_initiated)
 241                                 data = (s64)(s32)data;
 242                         pmc->counter += data - pmc_read_counter(pmc);
 243                         return 0;
 244                 } else if ((pmc = get_gp_pmc(pmu, msr, MSR_P6_EVNTSEL0))) {
 245                         if (data == pmc->eventsel)
 246                                 return 0;
 247                         if (!(data & pmu->reserved_bits)) {
 248                                 reprogram_gp_counter(pmc, data);
 249                                 return 0;
 250                         }
 251                 }
 252         }
 253
 254         return 1;
 255 }
 256
 257 static void intel_pmu_refresh(struct kvm_vcpu *vcpu)
 258 {
 259         struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
 260         struct kvm_cpuid_entry2 *entry;
 261         union cpuid10_eax eax;
 262         union cpuid10_edx edx;
 263
 264         pmu->nr_arch_gp_counters = 0;
 265         pmu->nr_arch_fixed_counters = 0;
 266         pmu->counter_bitmask[KVM_PMC_GP] = 0;
 267         pmu->counter_bitmask[KVM_PMC_FIXED] = 0;
 268         pmu->version = 0;
 269         pmu->reserved_bits = 0xffffffff00200000ull;
 270
 271         entry = kvm_find_cpuid_entry(vcpu, 0xa, 0);
 272         if (!entry)
 273                 return;
 274         eax.full = entry->eax;
 275         edx.full = entry->edx;
 276
 277         pmu->version = eax.split.version_id;
 278         if (!pmu->version)
 279                 return;
 280
 281         pmu->nr_arch_gp_counters = min_t(int, eax.split.num_counters,
 282                                         INTEL_PMC_MAX_GENERIC);
 283         pmu->counter_bitmask[KVM_PMC_GP] = ((u64)1 << eax.split.bit_width) - 1;
 284         pmu->available_event_types = ~entry->ebx &
 285                                         ((1ull << eax.split.mask_length) - 1);
 286
 287         if (pmu->version == 1) {
 288                 pmu->nr_arch_fixed_counters = 0;
 289         } else {
 290                 pmu->nr_arch_fixed_counters =
 291                         min_t(int, edx.split.num_counters_fixed,
 292                                 INTEL_PMC_MAX_FIXED);
 293                 pmu->counter_bitmask[KVM_PMC_FIXED] =
 294                         ((u64)1 << edx.split.bit_width_fixed) - 1;
 295         }
 296
 297         pmu->global_ctrl = ((1 << pmu->nr_arch_gp_counters) - 1) |
 298                 (((1ull << pmu->nr_arch_fixed_counters) - 1) << INTEL_PMC_IDX_FIXED);
 299         pmu->global_ctrl_mask = ~pmu->global_ctrl;
 300
 301         entry = kvm_find_cpuid_entry(vcpu, 7, 0);
 302         if (entry &&
 303             (boot_cpu_has(X86_FEATURE_HLE) || boot_cpu_has(X86_FEATURE_RTM)) &&
 304             (entry->ebx & (X86_FEATURE_HLE|X86_FEATURE_RTM)))
 305                 pmu->reserved_bits ^= HSW_IN_TX|HSW_IN_TX_CHECKPOINTED;
 306 }
 307
 308 static void intel_pmu_init(struct kvm_vcpu *vcpu)
 309 {
 310         int i;
 311         struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
 312
 313         for (i = 0; i < INTEL_PMC_MAX_GENERIC; i++) {
 314                 pmu->gp_counters[i].type = KVM_PMC_GP;
 315                 pmu->gp_counters[i].vcpu = vcpu;
 316                 pmu->gp_counters[i].idx = i;
 317         }
 318
 319         for (i = 0; i < INTEL_PMC_MAX_FIXED; i++) {
 320                 pmu->fixed_counters[i].type = KVM_PMC_FIXED;
 321                 pmu->fixed_counters[i].vcpu = vcpu;
 322                 pmu->fixed_counters[i].idx = i + INTEL_PMC_IDX_FIXED;
 323         }
 324 }
 325
 326 static void intel_pmu_reset(struct kvm_vcpu *vcpu)
 327 {
 328         struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
 329         int i;
 330
 331         for (i = 0; i < INTEL_PMC_MAX_GENERIC; i++) {
 332                 struct kvm_pmc *pmc = &pmu->gp_counters[i];
 333
 334                 pmc_stop_counter(pmc);
 335                 pmc->counter = pmc->eventsel = 0;
 336         }
 337
 338         for (i = 0; i < INTEL_PMC_MAX_FIXED; i++)
 339                 pmc_stop_counter(&pmu->fixed_counters[i]);
 340
 341         pmu->fixed_ctr_ctrl = pmu->global_ctrl = pmu->global_status =
 342                 pmu->global_ovf_ctrl = 0;
 343 }
 344
 345 struct kvm_pmu_ops intel_pmu_ops = {
 346         .find_arch_event = intel_find_arch_event,
 347         .find_fixed_event = intel_find_fixed_event,
 348         .pmc_is_enabled = intel_pmc_is_enabled,
 349         .pmc_idx_to_pmc = intel_pmc_idx_to_pmc,
 350         .msr_idx_to_pmc = intel_msr_idx_to_pmc,
 351         .is_valid_msr_idx = intel_is_valid_msr_idx,
 352         .is_valid_msr = intel_is_valid_msr,
 353         .get_msr = intel_pmu_get_msr,
 354         .set_msr = intel_pmu_set_msr,
 355         .refresh = intel_pmu_refresh,
 356         .init = intel_pmu_init,
 357         .reset = intel_pmu_reset,
 358 };